The belt is off. It was easier than expected. For anyone doing this down the road.
1) unfasten the spring to the belt idler pulley arm from the frame (hint: reattach with a 3" loop of chord using a screw driver to protect your hands while stretching the spring)
2 ) remove the idler pulley from the arm freeing the belt.
2) remove the 3 screws securing the variable pulley housing from below just over the axle. This provides adequate movement of the variable pulley to free the belt.
3) release the rear deck suspension arms from the mower deck. (these connect to brackets under the seat held in place by the cross shaft blocking access to the large 7/8 belt pulley flange nut.
3) jack the left rear tire off the ground, block up the axle, and remove the tire. (this step may not be essential as the cross shaft only has to move an inch or so to be freed where I had anticipated having to slide it out completely, and I was able to drive it the inch needed with the tire in place on the right side of the tractor)
4) remove the E clips retaining the cross shaft and, using a punch, knock the cross shaft from the right side to left of the tractor until it clears the frame. Easier if the plastic bushings are removed at each end as soon as practicable. The assembly can now be moved forward to access the large pulley nut
5) the large pulley shaft has flat sides beneath the pulley. Place an adjustable wrench across the flats and block it (I laid it against the idler pulley arm)
6) remove the large pulley nut and you are done. The nut is 7/8. I used a large Tractor ratchet with 10" extension. It came loose easily so might have gotten away with a box end.
Took a little over an hour and would have been half that knowing the above going in.